Citations

e16012 Background: 75–85% of bladder cancer patients present with non-muscle invasive disease (NMIBC). While transurethral resection of bladder tumors (TURBT) is the initial standard treatment for visible lesions, there is variation in the utilization of adjuvant intravesical treatments in the real world. This study aims to assess current treatment patterns in privately insured NMIBC patients. Methods: Bladder cancer patients were identified from Truven MarketScan Commercial and Medicare Supplemental databases using ICD-9/ICD-10 codes. In the absence of tumor staging information, patients were considered to have NMIBC based on diagnosis of CIS or an algorithm centered on the use of TURBT, intravesical treatments and absence of immediate progression to muscle invasive disease. Patients were included in the final cohort if they had one year of continuous insurance coverage prior to index diagnosis, and were without any bladder cancer treatment during this period. Results: 18,683 patients met the eligibility criteria and had a median follow-up of 23 months; the mean age was 68.6 years and 75% were male. The median time from diagnosis to TURBT was 8 days. 54% of the cohort had an intravesical treatment (35% specifically with Bacillus Calmette–Guérin (BCG), with median time from TURBT of 69 days). 77% of BCG-treated patients received 5 or more administrations during induction. However, only 22% of patients received maintenance BCG after induction. 16% of the total cohort developed a recurrence or progression during the available follow-up; five percent underwent a cystectomy, while seven percent were diagnosed with metastatic disease. Only 4% of patients with 5 or more BCG administrations during induction met the definition for being BCG-unresponsive; this is influenced by the low adherence to BCG maintenance protocol. Conclusions: Only a third of NMIBC patients are given intravesical BCG treatment. Adherence to BCG maintenance protocols is suboptimal. Rates of cystectomy/ exenteration are low, suggesting patients’ preference of bladder preservation and the unmet need for new bladder-sparing alternatives.

4521 Background: The MTAP gene encodes an essential enzyme for the salvage pathway of nucleotide synthesis and is frequently deleted in UBC. Anti-folate agents such as pemetrexed can effectively inhibit the de novo pathway of nucleotide synthesis and as a result, create a synthetic lethality in MTAP deficient UBC. We hypothesize that MTAP gene loss correlates with enhanced response to pemetrexed in UBC. Methods: We investigated MTAP gene deletion rates in the TCGA database and determined MTAP protein loss rates by immunohistochemistry (IHC) using a UBC tissue microarray (TMA) from 151 patients (pts). We then performed in vitro and in vivo studies using MTAP proficient and MTAP deficient bladder cancer cell lines. At the clinical level, we performed a retrospective analysis based on MTAP status of pts treated with pemetrexed as 2nd line at our institution between 2014 and 2018. We are now enrolling pts in a single-arm, open-label, phase II clinical trial (NCT02693717) with pemetrexed in pts with MTAP deficient UBC. Results: Per our TCGA and TMA IHC analyses, MTAP deficiency rate was 25.9% and 27.8%, respectively. MTAP deficient UBC cell lines were at least 40 times more sensitive to pemetrexed than MTAP proficient lines. Knockdown of the MTAP gene increased apoptosis rate by pemetrexed from approximately 20% to 60%. Additionally, pemetrexed significantly inhibited the growth of MTAP deficient or knockdown xenograft tumors but not MTAP proficient tumors. Retrospective analysis of 12 pts using RECIST criteria indicated that all 4 MTAP deficient UBC pts responded to pemetrexed whereas only 1 of 8 (12.5%) MTAP proficient UBC pts responded. Of the 6 pts enrolled on the clinical trial, 3 (50%) had complete or partial response, 1 had stable disease, 1 was not evaluable and 1 had disease progression. Combined analysis of the entire experience demonstrates a higher response rate in MTAP deficient UBC (70%) as compared to MTAP proficient UBC (12.5%). Conclusions: Our preclinical and clinical data demonstrate that MTAP loss in UBC leads to a state of synthetic lethality when treated with pemetrexed and should be further investigated as a novel biomarker to predict response to anti-folate agents.

e14237 Background: Targeting myeloid-derived suppressor cells (MDSCs), key mediators of intrinsic and adaptive immune resistance, remains a significant challenge in kidney cancer immunotherapy. One potential driver of MDSC mediated tumor immunosuppression is the cytokine interleukin-1 beta (IL-1β). Although large cancer prevention studies show that targeting IL1 decreases cancer risk, the exact mechanism of anti-IL-1 mediated anti-tumor efficacy is not yet defined. To understand the immunogenic effects of IL-1β blockade and effects on MDSCs, we used the RENCA model of RCC. Methods: We inoculated BALB/c mice with 1x106 RENCA cells. On Day +10 we treated mice (n = 8/group) with vehicle, αPD1, αIL1β, cabozantinib, combination αPD1/αIL1β, or cabozantinib/αIL1β. We harvested day +18 tumors to quantify tumor size and immune cells by flow cytometry. We then isolated immune cells for differential gene expression profiling by RNAseq. Results: Treatment with αIL1β significantly decreased tumor size compared to vehicle or αPD1 monotherapy. Combining αPD1/αIL1β or cabozantinib/αIL1β potentiated the anti-tumor effects of αPD1 or cabozantinib monotherapy respectively. Anti-IL1β therapy decreased polymorphonuclear (PMN)-MDSC infiltration (αIL1β: 0.76% +/- 0.21 vs. vehicle: 1.89% +/- 0.37, P = 0.014). Relative to PD1 monotherapy, combining αPD1 and αIL1β decreased PMN-MDSCs (αPD1: 2.14% +/- 0.56 vs αPD1/αIL1β: 0.91% +/- 0.15, P = 0.033) and increased M1-like tumor associated macrophages (TAM) (αPD1: 0.798% +/- 0.21 vs. αPD1/αIL1β: 12.04% +/- 2.9, P = 0.0008). Gene expression profiling from sorted immune cells from αIL1β treated tumors revealed multiple differentially regulated cytokines including interleukin-6, IFN-γ, and IL-10. Conclusions: Blockade of IL-1β depletes intratumoral PMN-MDSCs and increases M1-like TAM with minimal effects observed on the T cell compartment. Treatment with cabozantinib or αPD1 in combination with αIL1β led to sustained control of tumor growth. IL-1β represents a promising target for kidney cancer immunotherapy. Based on the preclinical data, a clinical trial of neoadjuvant αPD1 and αIL1β therapy is planned for patients with high risk RCC.

Background Patients with symptomatic severe aortic stenosis and a history of chest radiation therapy represent a complex and challenging cohort. It is unknown how transcatheter aortic valve replacement ( TAVR ) compares with surgical aortic valve replacement in this group of patients, which was the objective of this study. Methods and Results We retrospectively reviewed all patients with severe aortic stenosis who underwent either TAVR or surgical aortic valve replacement at our institution with a history of mediastinal radiation (n=55 per group). End points were echocardiographic and clinical outcomes in‐hospital, at 30 days, and at 1 year. Inverse propensity weighting analysis was used to account for intergroup baseline differences. TAVR patients had a higher STS score than surgical aortic valve replacement patients (5.1% [3.2, 7.7] versus 1.6% [0.8, 2.6], P <0.001) and more often ( P <0.01 for all) a history of atrial fibrillation (45.5% versus 12.7%), chronic lung disease (47.3% versus 7.3%), peripheral arterial disease (38.2% versus 7.3%), heart failure (58.2% versus 18.2%), and pacemaker therapy (23.6% versus 1.8%). Postoperative atrial fibrillation was less frequent (1.8% versus 27.3%; P <0.001) and hospital stay was shorter in TAVR patients (4.0 [2.0, 5.0] versus 6.0 [5.0, 8.0] days; P <0.001). The ratio of observed‐to‐expected 30‐day mortality was lower after TAVR as was 30‐day mortality in inverse propensity weighting–adjusted Kaplan–Meier analyses. Conclusions In patients with severe aortic stenosis and a history of chest radiation therapy, TAVR performs better than predicted along with less adjusted 30‐day all‐cause mortality, postoperative atrial fibrillation, and shorter hospitalization compared with surgical aortic valve replacement. These data support further studies on the preferred role of TAVR in this unique patient population.

Nuclear translocation of mothers against decapentaplegic homolog 2/3 (SMAD2/3), core transcription factors of transforming growth factor β (TGF‐β) signaling, is critical for hepatic stellate cell (HSC) differentiation into metastasis‐promoting myofibroblasts. SMAD2/3 have multiple coactivators, including WW domain‐containing transcription regulator protein 1 (WWTR1 or TAZ) and p300 acetyltransferase. In the nucleus, TAZ binds to SMAD2/3 to prevent SMAD2/3 nuclear export. However, how TAZ and SMAD2/3 enter the nucleus remains poorly understood because neither contains a nuclear localization signal (NLS), an amino acid sequence tagging proteins for nuclear transport. p300 is an NLS‐containing large scaffold protein, so we hypothesized that SMAD2/3 and TAZ may undergo nuclear import through complexing with p300. Coimmunoprecipitation, immunofluorescence, and nuclear fractionation assays revealed that TGF‐β1 promoted binding of SMAD2/3 and TAZ to p300 and that p300 inactivation disrupted TGF‐β1‐mediated SMAD2/3 and TAZ nuclear accumulation. Deleting the p300 NLS blocked TGF‐β1‐induced SMAD2/3 and TAZ nuclear transport. Consistently, p300 inactivation suppressed TGF‐β1‐mediated HSC activation and transcription of genes encoding tumor‐promoting factors, such as connective tissue growth factor, Tenascin C, Periostin, platelet‐derived growth factor C, and fibroblast growth factor 2, as revealed by microarray analysis. Chromatin immunoprecipitation‐real‐time quantitative PCR showed that canonical p300‐mediated acetylation of histones also facilitated transcription in response to TGF‐β1 stimulation. Interestingly, although both TGF‐β1‐mediated and stiffness‐mediated HSC activation require p300, comparison of gene expression data sets revealed that transcriptional targets of TGF‐β1 were distinct from those of stiffness‐p300 mechanosignaling. Lastly, in tumor/HSC coinjection and intrasplenic tumor injection models, targeting p300 of activated‐HSC/myofibroblasts by C646, short hairpin RNA, or cre ‐mediated gene disruption reduced tumor and liver metastatic growth in mice. Conclusion: p300 facilitates TGF‐β1‐stimulated HSC activation by both noncanonical (cytoplasm‐to‐nucleus shuttle for SMAD2/3 and TAZ) and canonical (histone acetylation) mechanisms. p300 is an attractive target for inhibiting HSC activation and the prometastatic liver microenvironment.

The NCCN Guidelines for Hepatobiliary Cancers provide treatment recommendations for cancers of the liver, gallbladder, and bile ducts. The NCCN Hepatobiliary Cancers Panel meets at least annually to review comments from reviewers within their institutions, examine relevant new data from publications and abstracts, and reevaluate and update their recommendations. These NCCN Guidelines Insights summarize the panel’s discussion and updated recommendations regarding systemic therapy for first-line and subsequent-line treatment of patients with hepatocellular carcinoma.

Background: The AMPLIFY randomized clinical trial showed that apixaban was associated with significantly lower major bleeding (MB) compared to warfarin for patients with venous thromboembolism (VTE). The main objective of this study was to compare the risk of major bleeding (MB), clinically relevant non-major bleeding (CRNM), and recurrent VTE among VTE patients treated with apixaban vs warfarin in the US Medicare population. Methods: Patients (aged ≥65 years) prescribed apixaban or warfarin within 30 days following a VTE event diagnosed in hospital or ambulatory setting were identified from 01SEPT2014-31DEC2016 using 100% CMS Medicare data. The first apixaban or warfarin prescription claim outside of the hospital was defined as the index date. Patients were required to have had continuous health plan enrollment for 6 months and no parenteral or oral anticoagulant use before the index VTE event. Outcomes were assessed from index date to the earliest of discontinuation, switch, health plan disenrollment, death, 6 months post-index date, or 31DEC2016. One-to-one propensity score matching (PSM) was used to balance patient characteristics. Cox proportional hazard models were used to estimate the risk of MB, CRNM bleeding, and recurrent VTE. Results: Among 37,799 patients meeting inclusion criteria, 25,284 patients initiated warfarin (66.9%) and 12,515 patients initiated apixaban (33.1%). Post-PSM, 11,363 matched pairs of apixaban-warfarin patients were identified, with a mean follow-up period of 4.0 and 4.4 months. Mean age was 78 years; nearly 37% of patients were male with a mean Charlson Comorbidity Index score of 2.9 in both groups. Apixaban was associated with a lower risk of MB (HR: 0.76; 95% CI: 0.64-0.91) and CRNM bleeding (HR: 0.77; 95% CI: 0.70-0.84) compared to warfarin. The risk of recurrent VTE was similar among apixaban and warfarin patients (HR: 1.04; 95% CI: 0.75-1.43; Figure). Conclusions: Among US Medicare patients with VTE, apixaban was associated with a lower risk of MB and CRNM bleeding and similar risk of recurrent VTE compared to warfarin. These results may be supportive in evaluating the risk-benefit ratio of apixaban for treatment of elderly VTE patients.

Intra-acinar trypsinogen activation occurs in the earliest stages of pancreatitis and is believed to play important roles in pancreatitis pathogenesis. However, the exact role of intra-acinar trypsin activity in pancreatitis remains elusive. Here, we aimed to examine the specific effects of intra-acinar trypsin activity on the development of pancreatitis using a transgenic mouse model. This transgenic mouse model allowed for the conditional expression of a mutant trypsinogen that can be activated specifically inside pancreatic acinar cells. We found that expression of this active mutated trypsin had no significant effect on triggering spontaneous pancreatitis. Instead, several protective compensatory mechanisms, including SPINK1 and heat shock proteins, were upregulated. Notably, these transgenic mice developed much more severe acute pancreatitis, compared with control mice, when challenged with caerulein. Elevated tissue edema, serum amylase, inflammatory cell infiltration and acinar cell apoptosis were dramatically associated with increased trypsin activity. Furthermore, chronic pathological changes were observed in the pancreas of all transgenic mice, including inflammatory cell infiltration, parenchymal atrophy and cell loss, fibrosis, and fatty replacement. These changes were not observed in control mice treated with caerulein. The alterations in pancreata from transgenic mice mimicked the histological changes common to human chronic pancreatitis. Taken together, we provided in vivo evidence that increased intra-acinar activation of trypsinogen plays an important role in the initiation and progression of both acute and chronic pancreatitis. NEW & NOTEWORTHY Trypsinogen is activated early in pancreatitis. However, the roles of trypsin in the development of pancreatitis have not been fully addressed. Using a genetic approach, we showed trypsin activity is critical for the severity of both acute and chronic pancreatitis.